Merge "Fix buffer producer being blocked when dequeing buffers." into main

namespace android {

namespace companion {

namespace virtualcamera {

namespace {

// Maximal number of buffers producer can dequeue without blocking.

constexpr int kBufferProducerMaxDequeueBufferCount = 64;

}  // namespace

EglSurfaceTexture::EglSurfaceTexture(const uint32_t width, const uint32_t height)

    : mWidth(width), mHeight(height) {

    return;

  }

  BufferQueue::createBufferQueue(&mBufferProducer, &mBufferConsumer);

  // Set max dequeue buffer count for producer to maximal value to prevent

  // blocking when dequeuing input buffers.

  mBufferProducer->setMaxDequeuedBufferCount(

      kBufferProducerMaxDequeueBufferCount);

  mGlConsumer = sp<GLConsumer>::make(

      mBufferConsumer, mTextureId, GLConsumer::TEXTURE_EXTERNAL, false, false);

  mGlConsumer->setName(String8("VirtualCameraEglSurfaceTexture"));

}

GLuint EglSurfaceTexture::updateTexture() {

  int previousFrameId;

  int framesAdvance = 0;

  // Consume buffers one at the time.

  // Contrary to the code comments in GLConsumer, the GLConsumer acquires

  // next queued buffer (not the most recently queued buffer).

  while (true) {

    previousFrameId = mGlConsumer->getFrameNumber();

    mGlConsumer->updateTexImage();

    int currentFrameId = mGlConsumer->getFrameNumber();

    if (previousFrameId == currentFrameId) {

      // Frame number didn't change after updating the texture,

      // this means we're at the end of the queue and current attached

      // buffer is the most recent buffer.

      break;

    }

    framesAdvance++;

    previousFrameId = currentFrameId;

  }

  ALOGV("%s: Advanced %d frames", __func__, framesAdvance);

  return mTextureId;

}